Sources within the committee caution that come Friday anything can happen, but even some of Steele's supporters privately acknowledge that his path to re-election is steep. They expect that his support could dwindle without an extremely strong showing on the first ballot.
Cino told ABC News that the chairman "has done a good job of conducting himself" during the race, but predicted that re-election would be "a big challenge for him."
Nevertheless, Steele backers like Michigan GOP committeewoman Holly Hughes have been helping him round up endorsements and on Monday night the chairman circulated a memo touting the RNC's accomplishments and rebutting much of the criticism that has been leveled by rivals.
"Over the past two years, by many key measures, the RNC has been more successful at that task than any committee in history," Steele wrote. "Notwithstanding the inside Washington noise, that is simply a fact. And, working together, our party can make sure that the next two years are even better."
Massachusetts RNC committeeman Ron Kaufman said that Priebus, who has the backing of one of the committee's most influential members -- Mississippi committeeman Henry Barbour, nephew of the state's Gov. Haley Barbour -- looks like he has considerable momentum going into this Friday's vote.
"Where that leads to is still up in the air," Kaufman said in an interview with ABC News. "RNC elections are kind of like conventions, once the gavel comes down it takes on a life of its own."
But other candidates have been seeking to throw cold water on reports that Priebus is the front-runner. Anuzis, who ran for RNC chair two years ago and lost, said that if Steele bows out after the first round of voting Priebus would have to lay claim to at least half of Steele's votes in order to win outright on the second ballot.
"Based on our internal count and that of other campaigns and RNC members, that seems highly unlikely," Anuzis wrote in a memo to his supporters. "Once Steele is out, the dynamics change. Reince may or may not hold onto all his votes and whatever 'anybody but Steele' votes he was able to rally early on in order to create Steele's vulnerability."
As Republican political strategist Mike Murphy pointed out in an online column, in some corners of the party, Priebus, who served until recently as the RNC's general counsel, is viewed as a Steele ally who betrayed the chairman while others perceive him as "too close to the old Steele regime."
"I think there is about a 60 percent chance that Priebus will take it, followed by a 35 percent chance for Anuzis and a 10 percent chance for a Cino upset," wrote Murphy, who is not a member of the committee.
The five candidates and their backers have been crisscrossing the country, making phone calls, sending volleys of e-mail messages and releasing action plans to shore up support ahead of the vote.
"Republicans are going to be faced with a billion dollar campaign that's going to be waged by Barack Obama in 2012," Cino said, noting that her past experience with the party would enable her to "walk in on January 15 with no on the job training."
She added, "It's not just a $20 million debt, it's a campaign that is coming at us like a freight train."
The vote for chairman will take place on Friday beginning at 10 a.m. ET during the RNC's winter meeting, which is being held at the Gaylord National Resort and Convention Center in National Harbor, Md.